The Endocrine Pancreas

Question 1

How do you calculate Body Energy?

Answer 1

Energy Intake - Energy Output

Question 2

Where is energy intake determined?

Answer 2

The feeding centre (promotes hunger and drive to eat)

The satiety centre (promotes fullness by supressing feeding centre)

Question 3

What is glucostatic theory?

Answer 3

Food intake is determined by blood glucose. As BG increases, the drive to eat decreases

Question 4

What is the lipostatic theory?

Answer 4

Food intake is determined by fat stores. As fat stores increase, drive to eat decreases.

Question 5

What is leptin?

Answer 5

A peptide hormone which is released by fat stores which depresses feeding activity

Question 6

Name the three categories of energy output?

Answer 6

Cellular work, mechanical work and heat loss

Question 7

Define Cellular Work

Answer 7

Transporting molecules across membranes, growth and repair, storage of energy

Question 8

Define mechanical work

Answer 8

Movement on a large scale, using muscle, or intracellularly

Question 9

Define heat loss

Answer 9

Associated with cellular and mechanical work. Accounts for half of our energy output

Question 10

Define metabolism

Answer 10

The integration of all biochemical reactions in the body

Question 11

What three elements make up metabolism?

Answer 11

Extracting energy from nutrients in food, storing that energy, utilising that energy for work

Question 12

What are anabolic pathways?

Answer 12

Build up

Synthesis of large molecules from smaller ones, usually for storage purposes

Question 13

What are catabolic pathways?

Answer 13

Break down

Degradation of large molecules into smaller ones, releasing energy for work

Question 14

What is the absorptive state?

Answer 14

Where ingested nutrients supply the energy needs of the body and excess is stored.

Question 15

When do we enter an absorptive state?

Answer 15

After eating

Question 16

What is a fasted state?

Answer 16

Where we rely on body stores to provide energy between meals and overnight

Question 17

What nutrient does the brain use?

Answer 17

Glucose

Question 18

What can hypoglycaemia result in?

Answer 18

Coma and death

Question 19

How is blood glucose maintained?

Answer 19

Via synthesising glucose from glycogen or amino acids

Question 20

What happens to glucose in diabetes?

Answer 20

Glucose cannot be taken up so BG rises and glucose is detected in the urine

Question 21

What is the normal range of blood glucose?

Answer 21

4.2-6.3 mM

Hypoglycemia = <3mM

Question 22

Where are endocrine hormones produced?

Answer 22

The Islets of Langerhans

Question 23

What are the four types of islet cells?

Answer 23

alpha, beta, delta and F Cells

Question 24

What do alpha islet cells produce?

Answer 24

GLUCAGON

Question 25

What do beta islet cells produce?

Answer 25

INSULIN

Question 26

What do delta islet cells produce?

Answer 26

SOMATOSTATIN

Question 27

What do F cells produce?

Answer 27

Pancreatic polypeptide

Question 28

When does insulin dominate?

Answer 28

During the fed state

Question 29

When does glucagon dominate?

Answer 29

During the fasted state

Question 30

What is the function of insulin ?

Answer 30

To stimulate glucose uptake and lower blood glucose concentration ALSO: -stimulates glycogen synthesis, increases amino acid uptake into muscle, increases protein synthesis, increases TAG synthesis, inhibits gluconeogensis, promotes K+ion entry into cells, has permissive effect on GH

Question 31

How is insulin synthesised?

Answer 31

As preproinsulin which is converted to proinsulin in ER

Question 32

Give examples of insulin sensitive tissues?

Answer 32

Muscle and adipose tissue

Question 33

How does insulin stimulate glucose uptake?

Answer 33

By stimulating GLUT-4 to migrate to cell membrane so glucose can be transported into cell. Insulin stimulation stops= GLUT 4 return to cytoplasmic pool

Question 34

Where is insulin degraded?

Answer 34

The kidneys and liver

Question 35

When is insulin released?

Answer 35

When BG conc is increased, when plasma amino acid conc. is increased, when glucagon has been stimulated

Question 36

When is insulin inhibited?

Answer 36

Low blood glucose conc, somatostatin synthesis, stress

Question 37

What is the function of glucagon?

Answer 37

To raise blood glucose ALSO: - increases glucogenolysis - increases gluconeogenesis - ketogenesis

Question 38

Where does glucagon act?

Answer 38

UPON THE LIVER

Question 39

Where is glucagon degraded?

Answer 39

The liver

Question 40

What occurs when Glucagon is released?

Answer 40

Blood glucose concentration increases

Question 41

When is glucagon released??

Answer 41

When [BG] is <5.6mM

Question 42

What stimulates glucagon release?

Answer 42

Low [BG], High [amino acid]. sympathetic innervation, epinephrine, cortisol, stress

Question 43

What inhibits glucagon release?

Answer 43

Glucose, FFA and Ketones, Insulin, Somatostatin

Question 44

What happens to insulin and glucagon during parasympathetic activity?

Answer 44

Increase in insulin, small increase in glucagon

Question 45

What happens to insulin and glucagon during sympathetic activation ?

Answer 45

Increase in glucose mobilisation, increase in glucagon, increase in epinephrine and inhibition of insulin

Question 46

What is the action of somatostatin?

Answer 46

To inhibit GI tract activity by slowing nutrient absorption

Question 47

Where is Somatostatin produced?

Answer 47

D cells of pancreas

Question 48

What is the effect of exercise on [BG]?

Answer 48

Glucose entry into skeletal muscle increases Insulin sensitivity increases

Question 49

What is type 1 diabetes?

Answer 49

An autoimmune disease where pancreatic Beta Cells are destroyed, thus ability to produce insulin is decreased.

Question 50

What occurs if type 1 diabetes is left untreated?

Answer 50

Starvation and death

Question 51

What occurs in type 2 diabetes?

Answer 51

Peripheral tissues lose sensitivity to insulin = INSULIN RESISTANCE

Question 52

How is type 2 diabetes treated?

Answer 52

Diet and exercise to try and restore insulin sensitivity Metformin Sulphonylureas

Question 53

What are some complications of diabetes?

Answer 53

Retinopathy, neuropathy, nephropathy, CV Disease